1. Field of the Invention
The present invention relates to an ultrasonic probe for obtaining ultrasound images by scanning endocavities of a patient. The present invention also relates to an ultrasound imaging apparatus including an ultrasonic probe.
2. Discussion of the Background
An ultrasound imaging apparatus is well known to be used for medical purposes. The ultrasound imaging apparatus repeats ultrasound pulse transmission by transducers provided in an ultrasonic probe to a body of a patient. The transmitted ultrasound returns to the transducers as ultrasound echo signals. By changing the transmission direction of the ultrasound pulse, ultrasound images are obtained based on ultrasound echo signals collected from a plurality of directions in the body.
As disclosed in Japanese Patent Application Publication No. P2001-178728, one type of the ultrasound imaging apparatus is an ultrasound diagnosis apparatus having an ultrasonic probe which is used in an endocavity of a patient. Such an ultrasonic probe is called an endocavity probe and is used for examinations for, for example, the oral cavity, the endorectal cavity, and the abdominal cavity.
FIG. 1 is an illustration showing a known laparoscopic examination.
As shown in FIG. 1, when an ultrasonic probe is used in the laparoscopic examination, an endocavity probe 100 is inserted into the abdominal cavity through one of a plurality of trocars punctured into the abdominal cavity of a patient P. The endocavity probe 100 is handled by an operator Q. The operator Q also handles an endoscope 200 inserted into the abdominal cavity of the patient P through another trocar. The operator Q handles the endoscope 200, observing images obtained by the endoscope 200 and displayed in a display 300, so as to obtain images of a desired part of the patient P. The operator Q handles the endocavity probe 100 and contacts transducers of the endocavity probe 100 with a part in the abdominal cavity so as to obtain ultrasound images including a target part such as a tumor, as examining the abdominal cavity through the endoscope display.
FIG. 2 is an illustration showing one exemplary case of using the endocavity probe 100 in the laparoscopic examination shown in FIG. 1. FIG. 2 shows a case that the endocavity probe 100 is used in a laparoscopy with, for example, an aeroperitoneum or a gasless laparolift technique (or an abdominal wall lift technique). In a typical aeroperitoneum, carbon dioxide gas or physiological saline is injected into the abdominal cavity through the trocar 400 so as to create a certain space in the abdominal cavity between an abdominal wall Pa and an organ Pb, such as, for example, a liver. Alternatively, in a typical gasless laparolift technique, the abdominal wall Pa may be mechanically lifted up so as to create a certain space. After the space has been provided, an insertion rod 100a of the above-described endocavity probe 100 is inserted into the abdominal cavity.
Since the abdominal wall is lifted up, the insertion rod 100a is required to have a sufficient length. Therefore, the insertion rod 100a typically has a length (e.g., 300-400 millimeters) enough to reach the organ Pb when the abdominal wall Pa is lifted up and also to scan difficult parts of the organ Pb.
In some cases, however, the insertion rod 100a is too long and it may become difficult for the operator Q to handle the endocavity probe 100. That is, the length of the insertion rod 100a in FIG. 2 may result in handling problems of the endocavity probe 100 in some cases. One example case is when the endocavity probe 100 is used for an organ (or any other tissues) at a shallow part from the abdominal wall Pa. The handling problems also depend on the body of the patient P. Another example is a case that the abdominal wall 100a is not lifted up, as shown in FIG. 3. In other words, none of the carbon dioxide gases, the physiological saline, and the mechanical lift-up may be used in an examination with the endocavity probe 100. The trocar may not be used, either. In these cases, the distance between the abdominal wall Pa and the organ Pb is not as long as when the abdominal wall Pa is lifted up. As a result, the insertion rod 100a applied in FIG. 2 becomes too long to handle for the case shown in FIG. 3.